9.45am: Good morning, nation of voters and overseas voyeurs. It's Thursday and the Guardian is covering politics in a live blog format. Tom McCarthy here in New York, and here's how the cookie is crumbling:

•Newt Gingrich went on NPR this morning and admitted he can't win the nomination. "I'm probably going to come in third in delegates," he said. Delegates of course being the coin of the realm, the only currency that counts. But Gingrich is staying in the race, he said, in case there's an open convention. In short, Gingrich called for chaos at the Republican National Convention.

•Rick Santorum is a legend in his own mind. The Times has the icky details. "If we are not successful in this election, I fear that we will be the generation that allows the torch [of freedom] to go out."

•President Barack Obama, the un-candidate, has embarked on a multi-state tour to promote his energy policies, after his administration announced it would fast-track an oil pipeline from Oklahoma to the Gulf of Mexico. On that note, check out our video up this morning about the scientist who claims to have bred algae capable of extreme energy output. Can algae replace oil?

•The Republican candidates (still plural) are pursuing pared-down schedules today, with the three who aren't Ron Paul holding one event each. Romney has a fundraiser in DC, Santorum is speaking in Texas (primary 29 May and Gingrich is at LSU. Go Tigers!

The videos produced by Jason Mattera of his heroic confrontations with celebrities are beautifully produced – lots of sharp cuts and splashy graphics aggrandizing the journalist and promoting his book. So it is with great regret that were are unable to bring you the full video of Mattera's recent confrontation with U2 lead singer Bono, in which he hammers his quarry mercilessly with questions about the singer's work in Africa and where the band pays taxes.

The reason we can't bring you the full video is that it has been removed from the Breitbart site: instead of confronting the actual Bono Mattera mistakenly confronted a Bono impersonator. As in, not actually Bono. Who, to his credit, is careful to disclaim any personal oversight of U2's tax picture.

Something tells us Jason Mattera has a sufficiently resilient self-regard to bounce back from what for others might be a crippling embarrassment.

10.11am: He doesn't win primaries, but Ron Paul still gets about 10% more web traffic than Mitt Romney. The Republican candidates combined, however, do not get as much traffic as the president's campaign site. Can Barack Obama once again mobilize the "Yes We Can" digital millions?

10.55am: Here's more from the interview on NPR's Morning Edition with Newt Gingrich. In effect, he admits defeat in the primary campaign and pins his hopes on a brokered convention.

It's clear that conservative voters deeply worry about Governor Romney and it's clear that governor Romney has so much money that he can grind his way towards the nomination despite all that. And the question is can he put together a majority of delegates before he runs out of primaries on June 26.

Santorum's not going to get to a majority; I'm probably going to come in third in terms of total delegates. But the question is until Romney has an aboslute majority, I don't think anybody's inclined to give him the nomination.

He went on to admit that he has "no incentive to get out of the way" before Romeny achieves a majority of delegates, and agreed with a suggestion by presenter Steve Inskeep that his "best hope" was a contested convention.

I think the possibility is very real that we could get to an open convention. I think, in an open convention, nobody knows what that would produce, and in that process I may well be there as the nominee or having a significant influence on the nominee.

Here's the full interview.

12.18pm: Barack Obama has been in Oklahoma this morning trailing his "all of the above" energy policy. He has directed federal agencies to fast-track a 485-mile pipeline from Oklahoma to refineries on the Texas Gulf coast that's intended to remove a bottleneck oil transportation system. "We're drilling all over the place," he said in New Mexico yesterday. And today om Cushing, OK, he seems to have acknowledged the tricky place he's in with the Keystone pipeline, saying Congress made it impossible for him to make an informed decision.

Here's AP's account:

Obama says experts needed a certain amount of time to review the Keystone project, which would have run from Canada to Texas. But he says Congress wanted to make its own timeline based on politics, which forced him to reject the project. The president says he is happy to review future permits for the Keystone pipeline.

At end of OK event woman heard telling President she was born at same hospital in Hawaii. He quipped: "Do you have YOUR birth certificate?"

12.51pm: Which party will women support in 2012? After weeks of men like Rick Santorum and Rush Limbaugh talking about contraception, a new Economist / YouGov poll shows President Obama leading Mitt Romney among women voters by a whopping 17 points, 55-38.

That number seems to have moved around quite a bit in March. A Washington Post/ABC News poll out March 11 found President Obama's approval among women holding steady from a month prior. In sharp contrast an NYT/CBS poll from March 12 showed President Obama's approval rating tanked among women in late February and early March, falling 12 points from 53 to 41 percent.

1.01pm: The gaffe that moved the market: Toymaker Ohio Art Co. has had its best day in the stock market in more than 30 years, according to a Bloomberg report, on strength of sales of a single product: the Etch A Sketch.

The thinly traded toymaker more than tripled to $12.50 on one transaction of 500 shares at 10:41 a.m. in New York on the over-the-counter market. It was the biggest intra-day move for the shares since at least 1980, according to data compiled by Bloomberg....

Ohio Art, based in Bryan, Ohio, began selling the toy in 1960, and it was its best-selling product until last year. The company has 369,000 shares available to the public, data compiled by Bloomberg show.

1.37pm: A web site devoted to Manhattan news has spied a famous name among the list of alleged clients tied to a prostitution ring recently discovered operating on the Upper East Side. The purported john's name: John. As in Edwards.

Presidential candidate John Edwards at a Habitat for Humanity event in New Orleans in 2007. Photograph: Alex Brandon/AP

Edwards, a North Carolina Democrat known for his support of unions and workers' rights, was John Kerry's running mate in 2004. He withdrew as a presidential candidate in 2008 after his affair with a campaign videographer came to light. His wife, Elizabeth Edwards, died of cancer in 2010. He faces ongoing prosecution on charges that he violated campaign finance laws in an effort to keep his mistress (the videographer) secret. He's had a tough few years.

BREAKING: Prostitution Ring Embarrassed by Association with John Edwards

UPDATE: The lawyer for the accused leader of the Manhattan brothel has denied that Edwards' name appears in connection with the case. My colleague Matt Williams reports:

Reports linking former US presidential candidate John Edwards to a New York prostitution service have been cast into doubt by the lawyer of the British woman accused of masterminding the high-end brothel.

Gary Greenwald, defence counsel for Scottish-born Anna Gristina, said he had "never heard" the Edwards' name being used in connection to the case.

It follows claims that a call girl working for the alleged brothel boss told investigators she was paid to have sex with Edwards, who is currently facing unrelated charges involving the alleged use of campaign funds to cover up an affair. ...

Speaking on Thursday, Greenwald seemed to be taken aback by claims of a link between his client and Edwards.

"I do not know what you are talking about. It is the first time I have heard it," he said, on being asked about the veracity of the allegations.

He added: "I have never heard John Edwards mentioned until you mentioned it."

Other sources contacted by the Guardian also expressed surprise over the claims. One person familiar with the case suggested that the allegation was "way, way out of the leftfield".

Gristina, originally from Kirkliston, near Edinburgh, was arrested last month and charged with one count of promoting prostitution.

2.03pm: Now some good news for Rick Santorum: Mitt Romney has gone on television and compared himself to a Magic 8 Ball <--SATIRE that bit isn't true.

What in fact has happened is that a new poll out from Rasmussen shows Santorum with a 12-point lead over Romney, 43-31, in the Louisiana primary this Saturday. Louisiana will award 46 delegates, not exactly enough for Santorum to make up his current deficit of 280 or so. A win there would allow Santorum, however, when this nominating race is finally over, to take quiet pride in the fact that he helped shut out Romney in the South. Louisiana would be Romney's sixth loss in the region, following South Carolina, Georgia, Alabama, Mississippi and Tennessee.

2.12pm: Romney adviser Eric Fehrnstrom, he of the "it's almost like an Etch A Sketch" line, demonstrates a sense of humor about having captured everything bad opponents say about his boss in one eloquent and universally familiar and powerful symbol:

2.45pm: A gem from former Clinton aide Paul Begala, in a Zeke Miller piece about how Romney does not exactly strike fear in the hearts of Democrats:

"Every time I look at the economy I fear we can't win," said Paul Begala, another Clinton White House aide who co-founded Priorities USA, the White House-blessed Super PAC. "Every time I look at the Republicans I think we can't lose."

3.09pm:From the comments: We made the point earlier that Mitt Romney hasn't won any southern states (Florida, with its unique demographic patchwork of retirees, urbanites, immigrants and transplant sun-worshippers, doesn't count).

The question is posed by bloopie2:

If Romney is at this time not winning many votes in the South, what would that mean for him in a general election against Obama? Not much, I would presume--he'd still get that vote?

Will Romney win the South against Obama? For historical context, check out this NY Times map of presidential results from 1992-2008 (it's cool; you can scroll between years and see which states flipped). The short answer is, the deep Bible Belt has been solid GOP territory since Barry Goldwater won Lousiana through Georgia in 1964. But that's not the whole South.

Southern boys like Jimmy Carter and Bill Clinton have done well in parts of the South; as you can see, Clinton won Appalachia and the Ozarks states, where Barack Obama was shut out in 2008. Clinton also won Georgia in 1992.

One key to Obama's 2008 victory was his twin wins in North Carolina and Virginia, southern states both. Clinton couldn't carry those, and neither could Gore or Kerry. Can Obama repeat his wins in North Carolina and Virginia this year? Rasmussen, the conservative pollster, has new numbers out today showing Obama beating Romney in Virginia by 9 points.

3.39pm: UPDATE 2 to our earlier report that John Edwards had been tied to a Manhattan prostitution ring. (In Update 1, a lawyer for the alleged leader of the ring said Edwards wasn't involved.) Now Edwards himself has "adamantly denied" a claim by a prostitute that she slept with him. The New York Times reports:

"Mr. Edwards categorically denies that he was involved with any prostitute or service," a lawyer for Mr. Edwards said, calling the allegations false and defamatory.

4.06pm: Should members of Congress be able to profit by using insider knowledge to play the stock market? If the answer seems like a no-brainer to you, you'll be happy to hear that lawmakers agree. The Senate today passed a new bill to restrict stock trading by legislators.

The Stop Trading on Congressional Knowledge Act, or Stock Act, now goes to President Obama for signature. The bill makes it illegal for a senator who might pick up something in a hearing or a representative with special knowledge of legislation about to be passed from profiting off that knowledge.

Watchdog groups and some lawmakers said the changes had weakened the bill by killing two important provisions added on the Senate floor in early February.

One provision would have regulated a growing industry that collects "political intelligence" from political insiders for the use of hedge funds, mutual funds and other investors. The second provision dropped from the bill would have given prosecutors powerful new tools to pursue public corruption cases.

Lawmakers facing reelection this year now have new anti-corruption legislation brag about. The bill passed the Senate 96-3 after passing the House 417-2.

4.36pm: Passions run high on the campaign trail. Things get said. Feelings may be hurt.

Stumping in Texas today, Rick Santorum said that people who think about voting for Mitt Romney might as well just stick with Barack Obama. He managed to get in an Etch A Sketch dig.

"You win by giving people the opportunity to see a different vision for our country, not someone who's just going to be a little different than the person in there," said Santorum. "If you're going to be a little different, we might as well stay with what we have instead of taking a risk with what may be the Etch A Sketch candidate of the future."

Mitt Romney's spokesman, Ryan Williams, replied to the news with a tweet. He used the hashtag #disgrace.

5.23pm: Will the Democrats hang on to their 53-47 Senate majority in 2013? Larry Sabato of the University of Virginia Center for Politics looks at the eight Senate race toss-ups this year and assesses their chances of flipping in his latest Crystal Ball report.

Increasingly, it looks likely that the winning party will have a smaller majority than the Democrats do now (53 seats) — if there is a majority at all. The tiny margin for the winning party will enable the new Senate to do what Senates do best: a whole lot of nothing (discounting talk, of course)....

The seat currently rated as a toss up that is likeliest to change hands is Montana, where Sen. Jon Tester (D) looks like a slight underdog against Rep. Denny Rehberg (R).... The toss up seat likeliest to go Democratic is New Mexico. The Land of Enchantment is heavily Democratic territory these days, and this one wouldn't even be on the radar had Sen. Jeff Bingaman (D) not retired.

•Congress moved to make it illegal for members to use insider knowledge to profit on stocks. The bill was stripped of its most forceful regulatory provisions before it was passed.

•Shares of Etch A Sketch traded wildly higher before closing up 140% on the day. This all was the result of an ill-advised comment a senior Mitt Romney aide made on CNN. Newt Gingrich pretended to feed an Etch A Sketch to an alligator. That's politics, folks.